Body-nearable laser scanning system with programmed mode for consecutively reading bar code symbols without system reactivation

ABSTRACT

A portable automatic code symbol reading system having a laser scanning engine mounted upon the hand of its operator to provide hands-free automatic laser scanning capabilities. The automatic code symbol reading system includes a battery power supply aboard its hand-mounted housing, and a power-conserving control subsystem for conserving the consumption of electrical power during automatic portable laser scanning operations. The control subsystem of the present invention has a plurality of control centers which control the operation of the system components in accordance with preselected system control operations. Each of the control centers is responsive to control activation signals generated by certain of the system components upon the occurrence of predefined conditions. Certain of the control centers are capable of overriding other control centers to provide diverse control capabilities. These control capabilities facilitate execution of intelligent functions and power consumption measures required during automatic, hands-free code symbol reading operations.

RELATED CASES

This is a continuation of application Ser. No. 08/632,899, filed Apr.16, 1996 which is a continuation of application Ser. No. 08/489,305filed Jun. 9, 1995 now abandoned, which is a continuation of applicationSer. No. 08/821,917 filed Jan. 16, 1992, now abandoned, which is acontinuation-in-part of application Ser. No. 07/583,421 filed Sep. 17,1990, now U.S. Pat. No. 5,260,553, and application Ser. No. 07/580,740filed Sep. 11, 1990 now abandoned.

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates generally to laser-based bar code symbol readingsystems, and more particularly to an automatic bar code symbol readingsystem having a compact lightweight, laser scanning engine arrangablefor mounting on the body of the user for hands-free scanningapplications.

2. Brief Description of the Prior Art

Various types of laser scanning devices are in use and have beendisclosed in the patent literature. Many of these scanners read barcodes, such as the Uniform Product Code (UPC), which are imprinted onproducts, labels affixed to products, or packaging for products.

One type of scanner is referred to as a slot scanner. Typically slotscanners are mounted beneath or at the checkout counter of a retailestablishment, such as a supermarket. Another type of scanner is ahand-held scanner. This type of scanner typically includes a gripportion held in one's hand to enable the scanner to be directed onto abar code so that the scan pattern produced by the scanner traverses thebar code symbol in order to read it.

In the last few years there has been increased development toward makinghand-held scanners extremely small and lightweight. One such scanner isdisclosed in my United States Letters Patent No. 4,930,848, whosedisclosure is incorporated by reference, and which is assigned to thesame Assignee as this invention. That scanner comprises a hand gripportion and a body portion. Within the body portion of the scanner is an"laser scanning engine" having all of the necessary optical, mechanicaland electrical components required to produce a laser beam scanningpattern for reading bar codes and for receiving light reflectedtherefrom to produce an electrical signal indicative thereof. Otherhand-held laser scanners are disclosed in the patent literature,including U.S. Pat. Nos. 4,387,297 (Swartz, etal.), 4,409,470 (Swartz,et al.), 4,460,120 (Swartz, etal.), 4,607,156 (Koppenall, etal.),4,706,248 (Swartz, etal.), and 4,575,625 (Knowles).

Although prior art hand-held scanners are capable of reading bar codesymbols, they all typically require that they be held in the hand of theuser so that the laser beam scanning pattern can be aimed at the barcode symbol. In the course of checking out customers' purchases at acheckout counter, a clerk is thus required to continually pick up thescanner, direct its laser beam onto the symbols to effect the reading ofthe symbols, and then either lay down the scanner between readings orbetween customers or place it in a support cradle or mount so that theclerk can use his or her hands for other purposes.

Thus, there is a great need in the art for a bar code symbol readingsystem that offers the features of a hand-held system, while enablinghands-free triggerless operation.

OBJECTS OF THE INVENTION

Accordingly, a general object of the present invention is to provide anautomatic bar code symbol reading system having a laser scanning engineof compact, lightweight construction, and which overcomes thedisadvantages of prior art systems.

It is a further object of the present invention to provide a compact,lightweight bar code symbol reading system which allows the hands of theuser to be free when the scanner is in use.

It is still a further object of this invention to provide a compact,lightweight bar code symbol reading system having a small laser scanningengine mountable to the body of the user for producing a laser scanningpattern during hands-free operation.

It is still a further object of this invention to provide a compact,lightweight bar code symbol reading system having a body mounted laserscanning engine which is connected to a processing unit which may bemounted on the body of the user or on some other structure.

It is still another further object of this invention to provide acompact, lightweight bar code symbol reading system which isbody-mountable and which automatically initiates operation of the laserscanner engine when the laser scanner engine is brought close to anobject with a coded symbol to be read.

SUMMARY OF THE INVENTION

These and other objects of the subject invention are achieved byproviding an automatic bar code symbol reading system for reading codedsymbols, e.g., UPC symbols, etc.

In the illustrative embodiment, the system comprises a laser scanningengine for producing a laser scanning pattern and a remote unit coupledthereto. The laser scanning engine having a compact lightweightconstruction, includes means for mounting the same on the body of theuser, e.g., on the wrist, head, etc. The user may conveniently positionthe laser scanning engine on his or her body so that the laser scanningpattern produced thereby is directed toward and traverses the codedsymbol to be read. The laser scanning engine is operably connected tothe remote unit by way of conducting means. In the illustrativeembodiment, the remote unit includes electrical means for processing anddecoding the signals received from the laser scanning engine andproducing symbol character data representative of the symbols read. Theremote unit may be also mounted on the body of the user or on somestationary support.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and advantages of the present invention will be readilyappreciated by reading the following Detailed Description of theIllustrated Embodiment in conjunction with the accompanying drawings,wherein:

FIG. 1 is a perspective view of an automatic portable bar code symbolreading system constructed in accordance with the present invention andcomprising a laser scanning engine shown mounted on a wrist of a userand with a remote unit connected thereto by way of a cable;

FIG. 2 is an enlarged sectional view of the laser scanner engine takenalong with line 2--2 of FIG. 1;

FIG. 3 is a side elevational view of one typical use of the system ofthe present invention, namely, a user seated at a counter with the laserscanning engine mounted on the user's wrist while the remote unit ismounted either on the user's body or alternatively at the counter;

FIG. 4 is a block functional system diagram of the automatic bar codesymbol reading system of the present invention, illustrating theprincipal components of the system integrated within the control systemthereof;

FIG. 5A is a block functional diagram of a first embodiment of thesystem activation means of the automatic bar code symbol reading systemof the present invention;

FIG. 5B is a block functional diagram of a second embodiment of thesystem activation means of the automatic bar code symbol reading systemof the present invention;

FIG. 6 is a block functional diagram of the bar code presence detectionmeans of the automatic bar code symbol reading system of the presentinvention;

FIG. 7 is a logical functional diagram of the first control means of thecontrol system of the present invention;

FIG. 8 is a logical function diagram of the second control means of thecontrol system of the present invention;

FIG. 9A is a functional block diagram of the third control means of thecontrol system of the present invention;

FIG. 9B is a flow chart of a control program carried out in the thirdcontrol means for the case of system-control operation No. 2 (i.e., pathoption 2) of the illustrative embodiment;

FIGS. 10A, 10B and 10C, taken together, show a high level flow chartillustrating three user-selectable courses of programmed systemoperation that the control system of the illustrative embodiment mayundergo;

FIG. 11 is a state diagram illustrating the various states that the barcode symbol reading system of the illustrative embodiment may undergoduring the course of its operation;

FIG. 12 is a side elevational view of the automatic bar code symbolreading system of FIG. 1, showing the laser scanning engine affixed to aglove worn on the user's hand, with the remote unit held in a holster oron a belt worn on the waist of the user;

FIG. 13 is an elevational view of the automatic bar code symbol readingsystem of FIG. 1, showing the laser engine mounted on a hat worn on theuser's head; and

FIG. 14 is an elevational view of the automatic bar code symbol readingsystem of FIG. 1, showing the laser engine mounted on a headband worn onthe user's head.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

Referring now in greater detail to the drawings, where like charactersrefer to like parts, the laser-based bar code symbol reading system ofthe present invention is shown in FIG. 1.

As illustrated, bar code symbol reading system 102 comprises a laserscanning engine 104 and a remote unit 110 connected together by way of acable 108. The laser scanning engine 104 is preferably constructed inaccordance with the teachings set forth in aforementioned U.S. Pat. No.4,930,848 and in co-pending U.S. Patent application Ser. No. 299,988,filed on Jan. 23, 1989, entitled Laser Scanner Engine with Folded BeamPath, and in co-pending U.S. Pat. application Ser. No. 07/300,018, filedJan. 23, 1989, entitled Bouncing Oscillating Scanning Device for LaserScanning Apparatus, all of which are assigned to the same Assignee ofthis invention, and whose disclosures are incorporated herein byreference.

The laser scanning engine disclosed in application Ser. No. 07/299,988is an extremely compact and lightweight device. That device includesbeam sweeping means, constructed in accordance with the teachings setforth in co-pending application Ser. No. 07/300,018, for sweeping forlaser beam through an arc to form a linear single line scanning pattern.The laser scanning engine is contained within a housing 112 which alsoincludes various optical components for folding and forming laser beampath downstream of the beam sweeping means so as to increase the focallength of the beam, and thereby allow for a smaller beam scan angle thenotherwise possible with such a compact housing. Thus features enableaccurate and reliable reading of coded symbols located close to andsubstantially far away from the laser scanning engine 104. The beamsweeping means includes an oscillating mirror system constructed in sucha manner so that the speed of oscillations is substantially linearbetween reversals instead of the sinusoidal speed variation exhibited byprior art oscillating mirror devices.

As shown in FIG. 1, the laser scanning engine 104 is arranged forconvenient mounting on a portion of the body of the user, e.g., on thewrist of a user by way of a strap 106. The cable 108 serves to carry theelectrical signal produced by the laser scanning engine (and which isrepresentative of the bar code) to the remote unit 110 where the signalis processed, e.g., decoded. Electrical power for the laser scanningengine is also provided from the remote unit 110 by way of cable 108.

As shown in FIG. 2, the laser scanning engine 104 includes asemi-conductor laser diode 116 with an associated focusing means 118 forproducing a focused laser light beam 120. The laser light beam 120 isprojected within the housing 112 of the laser scanning engine onto abeam sweeping mechanism 134 (constructed in accordance with theteachings set forth in patent application Ser. No. 07/300,018). The beamsweeping mechanism includes a planar mirror 122 which is oscillated backand forth to sweep the laser beam 120 through an arc to thereby createthe laser scan line 114 when projected onto a surface. The line isultimately projected out of the window 111 of the engine for traversingthe bar code symbol to be read.

In order to fold the swept laser beam within the housing downstream ofthe beam sweeping means, i.e., between the beam sweeping means andwindow 111, the laser scanning engine also includes the beam foldingmeans constructed in accordance with the teachings set forth inapplication Ser. No. 299,988. Thus, as can be seen, the laser beam isfirst directed from the scanning or oscillating mirror 122 onto astationary mirror 124 mounted on the front end wall 112A of the housing112. The stationary mirror 124 reflects the beam upward to a mirror 126fixedly mounted on the rear end wall 12D of the housing. The mirror 126is angled slightly downward so that the reflected beam is directedgenerally horizontally within the housing out through the window 111 inthe front end wall 112A to create a linear scan line 114 when projectedon a planar surface, e.g., a surface bearing a bar code.

The light reflected back from the bar code passes through the window 111where it is received by mirror 126 and reflected back to mirror 124 andfrom there to the oscillating mirror 122. The oscillating mirrorreflects the received light back to a fixed collecting mirror 128. Thefixed collecting mirror 128 includes a spherical concave surface forfocusing received light onto a phototransistor 130. The phototransistor130 converts the reflected light into an electrical signal indicativethereof and provides that signal by way of cable 108 to the remote unit110.

As the laser scanning engine of the illustrative embodiment operatesaccording to retroflective design principles, with its collecting mirror128 located between the laser diode 116 and the scanning mirror 122, ittherefore includes an opening or hole 132 in collecting mirror 128 inorder to enable the outgoing laser beam to pass therethrough to the beamsweeping (oscillating) mirror 122.

In FIG. 3, the bar code symbol reading system is shown arranged for usein one typical application. In this application, the system is worn by aclerk or other person at a checkout counter of a store, at a checkoutcounter of a library, or some other venue. In particular, the laserscanning engine 104 is mounted on the wrist of the clerk by way of strap106. In order to scan a bar code symbol, all that is necessary is forthe clerk to hold up his or her arm with the laser scanner enginesupported thereon so that the light transmission window 111 of the laserscanning engine is directed toward the bar code symbol, whereupon thelaser beam pattern 114 is projected onto the bar code symbol to be read.This action leaves the operator's hands free for other purposes. Thelaser light reflected back from the bar code symbol passes through lighttransmission window 111, through the beam folding optics, theoscillating mirror and the collecting mirror to the phototransistorwhich converts the received light into an electrical signal indicativeof the scanned bar code symbol. The produced electrical signal isprovided by way of cable 108 to the remote unit 110 for processing in aconventional manner.

As shown in FIG. 3, the remote unit 110 comprises a housing in which itsoperational components, e.g., circuit boards, power supply, etc., arelocated. The remote unit 110 may be worn on a belt 137 or disposed in aholster (not shown) located on the waist of the user. Alternatively, theremote unit 110 may be mounted at the counter 116 itself. Thisalternative embodiment is shown by the phantom lines drawn in FIG. 3.

In general, remote unit 110 employs components and performs functionswhich are well known in the bar code symbol reading art. In theillustrative embodiment, remote unit 110 includes signal processing anddecoding circuitry for processing the electrical signal received fromthe laser scanning engine into an electrical signal containing theinformation of the coded symbol (i.e., symbol character data). Thissignal may be stored in the remote unit for later retrieval, or may bepassed on to some piece of peripheral equipment 142, such as a cashregister, a computer, or any other terminal by way of any suitable means(not shown), e.g., an RS232 port. As shown in FIG. 3, remote unit 110may also include an RF transceiver 141 for transmitting the processedelectrical signal, e.g., symbol character data associated with thedecoded symbol, to peripheral equipment such as a host computer, or datacollection device 142.

Inasmuch as the bar code symbol reading system of FIGS. 1 and 3 iscompletely portable, the remote unit 110 also includes a power supply,e.g., a battery 143, for supplying electrical power to the laserscanning engine 104 by way of the cable 108.

It should by noted that no trigger or other hand operated device isrequired to activate or deactivate the automatic bar code symbol readingsystem of the present invention. An energy transmitter and receiver andassociated circuitry of the kind disclosed in U.S. patent applicationSer. No. 07/583,421 for a "Method and Apparatus for AutomaticallyReading Bar Code Symbols", filed on Sept. 17, 1990, now U.S. Pat. No.5,260,553 and whose disclosure is incorporated herein, may be used toautomatically activate the automatic bar code symbol reading systemhereof. This aspect of the present invention is best appreciated withreference to the system of FIGS. 4 to 11, described below.

As shown in FIG. 4, bar code symbol reading system 102 comprises anumber of system components, namely, system activation means 2, scanningmeans 3 (e.g., mirror 122 and motor 134), photoreceiving means 4 (e.g.,collecting mirror 122 and photoreceiver 130), bar code presencedetection means 5, analog-to-digital (A/D) conversion means 6, symboldecoding means 7, data format conversion means 8, symbol character datastorage means 9, and data transmission means 10. As illustrated in FIG.4, these system components are embedded within a programmable controlsystem having a unique architecture which provides a great degree ofversatility in system capability and operation, as well as powerconservation. The structure, function and advantages of this controlsystem architecture will be described in great detail hereinafter.

The control system of the present invention comprises essentially threemajor components, namely first control means (C₁) 11, second controlmeans (C₂) 12, and third control means (C₃) 13. As will be described ingreater detail hereinafter, second control means 12 is capable of"overriding" (i.e., exhibit and/or enable) first control means 11,whereas third control means 13 is capable of overriding second controlmeans 12 and first control means 11. As shown in FIG. 4, such controloverride functions are carried out by the generation of control overridesignals (i.e., C₁ /C₂, C₁ /C₃, and C₂ /C₃) transmitted betweenrespective control structures.

As illustrated in FIG. 1, battery power supply 143 in remote unit 110provides the requisite electrical power to each of the system componentsof FIG. 4, when and for time prescribed by the control system hereof.Typically, an on/off power switch or functionally equivalent device willbe provided external to housing 112 to permit the user to empower theautomatic bar code symbol reading system. When power switch is initiallyengaged to its ON position, power will only be provided to systemactivation means 2 to enable its operation, while, for example, onlybiasing voltages and the like are provided to all other systemcomponents so that they are each initially disabled from operation.

FIG. 5 is a logical function diagram of the first control means of thecontrol system of the present invention;

In accordance with the present invention, the purpose of systemactivation means 2 is to produce first control activation signal A₂ upondetermining (i.e., detecting) the presence of an object (e.g., product,document, etc.) within the scan field of bar code symbol readingdevice 1. In turn, first control activation signal A₁ is provided asinput to both first and third control means 11 and 13, respectively. InFIGS. 5A and 5B, two different approaches to generating first controlactivation signal A₁ are disclosed.

In FIG. 5A, a passive technique is illustrated, in which passivedetection of ambient light within the scan field is performed in orderto determine if an object is present within the scan field 114 of theautomatic bar code symbol reading system 1. As illustrated in FIG. 5A,passive ambient light detection circuit 2A comprises a pair of photodiodes 15A and 15B, which sense ambient light gathered from twodifferent parts of the scan field in front of the light transmissionwindow 111 of housing 112, using focusing lenses 16A and 16B,respectively. The output signals of photodiodes 15A and 15B areconverted to voltages by current-to-voltage amplifiers 17A and 17Brespectively, and are provided as input to a differential amplifier 18.The output of differential amplifier 18 is provided as input to a sampleand hold amplifier 19 in order to reject 60 and 120 Hz noise. Outputsignal of amplifier 19 is provided as input to a logarithmic amplifier20 to command signal swing. The output signal of logarithmic amplifier20 is provided as input to a differentiator 21 and then to a comparator21. The output of comparator 21 provides first control activation signalA₁ .

In FIG. 5B, an active technique is illustrated in which an infraredsignal is transmitted out into the scan field and first controlactivation signal A_(I) is generated upon receiving a reflection of thetransmitted signal off an object within the scan field. As illustratedin FIG. 5B, infrared object detection circuit 2B comprises a synchronousreceiver/transmitter 22, which includes an infrared LED 23 whichgenerates a 900 nanometer pulsed signal at a rate of 2.0 KHZ. Thispulsed signal is transmitted through focusing lens 23 to illuminate thescan field. When an object is present within the scan field, a reflectedpulse signal is produced and focused through focusing lens 24 ontophotodiode 25. The output of photodiode is converted to a voltage bycurrent-to-voltage amplifier 26, and the output thereof is provided asinput to receiver/transmitter 22, to synchronously compare the receivedsignal with the transmitted signal and determine if an object is presentin the scan field. If so, then synchronous receiver/transmitter 22produces first control activation signal A₁ =1 indicative of suchcondition. First control activation signal A₁ =1, upon being generated,activates first control means 11 which, in turn, enables operation ofscanning means 3, photoreceiving means 4, and bar code presencedetection means 5, as will be described in greater detail hereinafter.In order to conserve power and improve signal-to-noise ratio atphotoreceiving means 4 during scan data collection operations, it ispreferable for first control means 11 to generate and provide a disablesignal E_(O) to infrared object detection circuit 2B whenever firstcontrol means 11 enables the scanning means 3.

As illustrated in FIGS. 4 and 7, first control means 11 is preferablyrealized by a circuit capable of generating enabling signals E₁, E₂ andE₃ for the scanning means, photoreceiving means and bar code presencedetection means, respectively. As will be described in detailhereinafter, the specific operation of first control means 11 isdependent on the state of three sets of input signals, namely, firstcontrol activation signal A, C_(l) override signals from C₂ (i.e., C₁/C₂ inhibit signal and C₁ /C₂ enable signal), and C₁ override signalsfrom C₃ (i.e., C₁ /C₃ inhibit signal and C₁ /C₂ enable signal). Asshown, first control activation control signal A₁ is provided to the"START" input of timer 28 upon which it produces a "high" output signalfor a first predetermined time period (i.e., T₁ seconds). Preferably,time period T₁ is selected to be about 0.3 seconds.

As illustrated in FIG. 7, the output signal of timer 28 is provided asan input to AND gate 29, with its other input connected to the RESETinput of timer 28. The output of AND gate 29 is provided as an input toeach of OR gates 30, 31 and 32. The C₁ /C₂ inhibit signal from secondcontrol means 12 and the C₁ /C₃ inhibit signal from third control means13 are provided as inputs to NOR gate 33, whereas C₁ /C₂ enable signalfrom second control means 12 and the C₁ /C₃ enable signal from thirdcontrol means 13 are provided as inputs to OR gate 34. As shown, theoutput signal of OR gate 34 is provided to the other input of OR gates30 and 31, whereas the output signal from NOR gate 33 is provided asinput to AND gate 29. The C₁ /C₃ enable signal is also provided as inputto OR gate 32, to complete the description of the circuit realization offirst control means 11. As indicated in FIG. 7, the outputs of OR gates30, 31 and 32 provide enable signals E₁, E₂ and E₃ for the scanningmeans, photoreceiving means and bar code presence detection means,respectively. Notably, disable signal E_(O) is produced from the outputof OR gate 30.

As illustrated in FIGS. 2 and 4, scanning means 3 comprises a lightsource 116 which, in general, may be any source of intense lightsuitably selected for maximizing the reflectively from the object. Inthe preferred embodiment, light source 116 comprises a solid-statevisible laser diode (VLD) which is driven by a conventional drivercircuit 37. As shown in FIGS. 2 and 4, the laser beam output from laserdiode 116 is swept over scan field 114 (having a predetermined spatialextent in front of front portion of housing 112), by scanning mirror 122being oscillated back and forth by stepper motor 134 in response tobeing driven by a conventional driver circuit 40, as shown. Toselectively activate both laser light source 116 and motor 134, thescanning means enable signal E₁ is provided as an input to both drivercircuits 37 and 40. When enable signal E₁ is a logical "high" level(i.e., E₁ =1), scanning means 3 is operable, a laser beam is generatedand scanned across the scan field, and scan data is thereby produced offany object residing within the scan field.

In a conventional manner, when an object, such as product bearing a barcode symbol, is within the scan field at the time of scanning, the laserbeam incident thereon will be reflected, producing a laser light returnsignal of variable intensity which represents a spatial variation oflight reflectivity characteristic of the spaced apart pattern of barscomprising the bar code symbol. Photoreceiving means 4 is provided forthe purpose of detecting at least a portion of laser light of variableintensity, which is reflected off the object and bar code symbol withinthe scan field. Upon such detection, photoreceiver 130 produces ananalog data signal D₁ indicative of the detected light intensity. Ingeneral, scan data collection optics, namely focusing mirrors 122, 124,126, and 128, focus scan data signals for subsequent detection byphotoreceiver 130. Photoreceiver 130, in turn, produces an analog signalindicative of the intensity of the scan data signal, which issubsequently amplified by preamplifier 43 to produce analog scan datasignal D₁. In combination, scanning means 3 and photoreceiving means 4operate to generate scan data from the scan field, over time intervalsspecified by first control means 11 during normal (i.e.,noncontrol-override) modes of operation, and by third control means 13during "control override" modes of operation. As will illustratedhereinafter, this scan data is used by both bar code presence detectionmeans 5 and symbol decoding means 6.

As illustrated in FIG. 4, analog scan data signal D₁ is provided asinput to both bar code presence detection means 5 as well as A/Dconversion means 6. The primary purpose of bar code presence detectionmeans 5 is to determine whether a bar code is present in or absent fromthe scan field, over time intervals specified by first control means 11during normal modes of operation and by third control means 13 duringcontrol override modes of operation. When the presence of a bar codesymbol in the scan field is determined, the bar code presence detectionmeans 5 generates second control activation signal A₂ (i.e., A₂ =1)which is provided as input to second control means 12, as shown in FIG.4.

As illustrated in FIG. 6, bar code presence detection means 5 isprovided with enable signal E₃ which is used to enable circuitryemployed in the realization of the bar code presence detection means. Inthe preferred embodiment, bar code presence detection means 5 isrealized as a bar code envelope detector circuit which processes analogscan data signal D₁ so as to produce a signal, the intensity of whichindicates the general envelope of a bar code within the scan field. Uponsuch detection, bar code envelope detection circuit 5 produces secondcontrol activation signal A₂ =1 which is provided as input to secondcontrol means 12.

As shown in FIG. 6, analog scan data signal D₁ is provided as input to adifferentiator 44 comprising capacitance element C₁ and resistiveelement R₁, to produce the first derivative signal of signal D₁. Thefirst derivative signal is then amplified by a differential outputamplifier 45, to produce as output amplified positive and negative firstderivative signals, which in turn are provided as input to a positivepeak detector 46. The output signal of positive peak detector 46 isprovided as input to a comparitor 47 which generates positive andnegative bar cede detect (BCD) signals.

As illustrated in FIG. 6, the positive and negative BCD signals are thenprovided as input and RESET signals to both integrators 48A and 48B.Positive BCD signal is also provided as input to pulse generator 50,which generates pulses upon the detection of the negative edges of thepositive BCD signal. As shown, the output signals of integrators 48A and48B are provided as first inputs to comparitors 49A and 49Brespectively, whereas an envelope border threshold voltage V₁ and barcode threshold voltage V₁ are provided as second inputs to comparitors49A and 49B, respectively. Boarder voltage V₁ is a DC reference voltagewhose value can be determined on the basis of the time constant ofintergrater 48A, its gain, and the time duration of the minimum required"boarder width" of the bar code symbol. Bar code threshold V₂ is also aDC reference voltage whose value can be determined on the basis of thetime constant of intergrater 48B, its gain, and the time duration of theminimum required "bar code length".

The output of comparitors 49A and 49B are provided to the "S" gates oflatches 51 and 52, respectively, and the "Q" gates of these latches areprovided as inputs to AND gate 53, as shown in FIG. 6. The output of ANDgate 53 is provided as input to the "S" gate of latch 54, whereas the"R" gate of latch 54 is connected to the "R" gate of latch 51. Theoutput of pulse generator 50 is provided as input to the "R" gate oflatch 52. The output of latch 54 provides second control activationsignal A₂, which in turn, is provided as input to second control means12, as shown in FIG. 4. The operation of the bar code envelope detector5 is essentially as follows. If the output signals of both comparitors49A and 49B go "high" before the next RESET pulse from pulse generator50 is provided to latch 52, then the output of latch 54 will go "high"(i.e., A₂ =1) indicating that a bar code is present in the scan field.

In general, when the presence of a bar code in the scan field isdetected, second activation control signal A₂ is generated, secondcontrol means 12 is activated and first control means 11 is overriddenby second control means 12 through the transmission of control overridesignals (i.e., C₁ /C₂ inhibit and C₁ /C₂ enable signals) from the secondcontrol means.

As illustrated in FIG. 8, second control means 12 preferably includes atiming means 55 whose output signal remains high for a secondpredetermined time period T₂. Preferably, time period T₂ is selected tobe about 1.0 seconds. Second control activation signal A₂ is provided tothe start input of timing means 55, while the output thereof is providedas an input to AND gate 56, as shown. Third control means 13 provides apair of C₂ override signals (i.e., C₂ /C₃ A and C₂ /₃ B), as input tosecond control means 12, as shown in FIG. 4. The C₂ /C₃ inhibit signalis provided to the second input of timing means 55. The C₂ /C₃ enablesignal, on the other hand, is provided to the first input of OR gates 57and 58, whereas the output of AND gate 56 is provided as second input toeach of OR gates 57 and 58. As illustrated in FIG. 8, the output signalof timing means provides both C₁ /C₂ inhibit and C₁ /C₂ enable signals,whereas the output of OR gates 57 and 58 provides enable signals E₄ andE₅ for enabling A/D conversion means 6 and symbol decoding means 7,respectively.

Upon detecting the presence of a bar code symbol in the scan field,second control activation signal A₄ activates second control activationmeans 12, which, in turn, directly enables A/D conversion means 6 andsymbol decoding means 7 by enabling signals E₄ and E₅, respectively.Indirectly, second control means 12 enables scanning means 3 andphotoreceiving means 4 and disables bar code presence detection circuit5 by providing C₁ override signals to first control means 11.

A/D conversion means 6 can be realized by any conventional A/D circuitor chip known in the bar code symbol reading unit, and functions toconvert analog scan data signal D into a digital scan data signal D₂,corresponding to the detected intensity of laser light collected anddetected at photoreceiving means 4. The digitized scan data signal D₂ isprovided as input to symbol decoding means 7, which scan line by scanline, decodes processes in a conventional manner, the stream ofdigitized scan data. The decoding means 7 processes a scan line of thedigital scan data at a time, in an attempt to decode a valid bar codesymbol within the second predetermined time period T₂ established andmonitored by timing means 55 of second control means 12. If decodingmeans 7 successfully decodes a bar code symbol within time period T₂,then symbol character data D₃ (typically in ASCII code format) isproduced corresponding to the decoded bar code symbol. Thereupon thirdcontrol activation signal A₃ is produced by symbol decoding means 7 andis provided to third control means 13 to activate the same. In response,third control means 13 provides override control signals to firstcontrol 11 and second control means 12, as described hereinabove.

As illustrated in FIGS. 4, 9A and 9B, third control means 13 of theillustrated embodiment generates and provides enable signals F₆, E₇ andF₈ to data format conversion means 8, data storage means 9 and datatransmission means 10. As shown, symbol decoding means 7 provides symbolcharacter data D₃ to data format conversion means 8 to convert data D₃into two differently formatted types of symbol character data, namely D₄and D₅. Format-converted symbol character date D₄ is of the "packeddata" format, particularly adapted for efficient storage in data storagemeans 9. Format-converted symbol character data D₅ is particularlyadapted for data transmission to a Data Storage Device such as CMOSmemory 144 in remote unit 110. When symbol character data D₄ is to beconverted into the format of the users choice based on a selected optionmode, third control means 13 generates and provides enable signal E₆ todata storage means 9, as shown in FIG. 4. Similarly, when formatconverted data D₅ is to be transmitted to CMOS memory 144, the thirdcontrol means 13 generates and provides enable signal E₈ to datatransmission means 10, which thereupon transmits format-converted symbolcharacter data D₅ to CMOS memory 144, by way of cable 108.

In the illustrated embodiment, third control means 13, symbol decodingmeans 7, and data format conversion means 8 and data storage means 9 arerealized using a single programmable device, such as microprocessor 63having accessible memory and external timing means. In this way,conventional symbol decoding and data format conversion processing canbe implemented in a straightforward manner. As for programmingmicroprocessor 63 to realize third control means 13 and the controlfunctions which it performs in the illustrative embodiment, reference ismade to FIG. 4, 5, 6, 7A and 7B in particular. In order to illustratethe nature of this programming and how it can be realized starting froma high level flow chart, System-Control Operation No. 2, illustrated inFIGS. 10A and 10B, will be used as an example.

In FIG. 9A, the third control means is shown implemented with a timer 64and microprocessor 63, whose input pins I₁ through I₄ and output pins O₁through O₈ are utilized in achieving the control functions performedduring System-Control Operation No. 2. In order to illustrate theprogrammed operation of the third control means during System-ControlOperation No. 2, reference is made to FIGS. 9A and 9B of the drawings.

In FIG. 9A, the output of timer 64 is provided to input pin I₄ ofmicroprocessor 63, whereas outputs 0₇ and O₈ thereof are provided asstart and reset signals respectively, to timer 64 as shown. Timer 64 isselected to elapse at T₃, which preferably will be about 2-3 seconds.Notably, each input I₁ through I₄, output O₁ through O₈, controlactivation signals A₁ through A₁, and enable signal E₁ through E₈, maytake on either a logical "high" value (i.e., 1), or a logical "low"value (i.e., 0). As illustrated in FIGS. 10A and 10B, during progressionthrough System-Control Operation No. 2, the presence of third controlactivation signal A₃ (i.e., A₃ =1) activates third control means 13. Thepresence of such signal value at the third control means indicates avalid bar code symbol has been decoded by symbol decoder 7. At the pointof activation of third control means 13, the possible logical operationsthat may occur therewithin (illustrated in flow chart of FIG. 9B), aredependent upon the condition of the first and second control activationsignals A₁ and A₂ and the input I₄ from the output timer 64.

As illustrated in FIG. 9B, if control activation signals A₃ input at 13is "low" (i.e., A₃ =0), then the control program of the third controlmeans returns to "start" and once again continuously senses for thepresence of third control activation signal (i.e., A₃ =1). Otherwise, ifthird control activation signal A₃ input at I₃ is high (i.e., A₃ =1),then the control program outputs O₂, O₃ and O₇ as high, inhibiting firstand second control means 11 and 12, and starting timer (T₃) 64, whiletoggling outputs O₅ and O₆ to enable data format conversion means 8 anddata storage means 9 or data transmission means 10.

Then, the control program proceeds to determine whether the firstcontrol activation signal A₁ at input I₁ is absent (i.e., A₁ =0),indicative of no object in scan field; if so, then the control programresets outputs O₂ and O₃ to return control to the inhibited first andsecond control means, while toggling output 0₈, to reset timer (T₃) 64.Otherwise, if input I₁ is high, indicative of an object in the scanfield, then the control program outputs O₁ as high, enabling thirdcontrol means 13 to override first control means 11, while enablingscanning means 3 photoreceiving means 4 and bar code presence detectioncircuit 5.

The control program then determines whether second control activationsignal A₂ at input 12 is low (i.e., A₂ =0), indicative of there being nobar code present in the scan field; if so, the program resets outputs O₂and O₃ to return control to the first and second control means, whiletoggling output O₈ to reset timer (T₃) 64 Otherwise, if second controlactivation signal A₂ at I₂ is high (i.e., A₂ =1) indicative of a barcode present in the scan field, then the control program progresses todetermine whether the output of timer 64 at input I₄ has gone low,indicative of timer T₃ elapsing (i.e., t>T₃). In this event, the controlprogram resets output O₁ to disable scanning means 3, photoreceivingmeans 4 and bar code detection means 5. If the input at I₁ is not low(i.e., A₁ =1) indicative of timer 64 not yet elapsed, then the controlprogram continues to determine whether the input at I₂ has gone low (A₂=0), indicative that a bar code symbol is no longer in the scan field.The control program will continue to repeat the above-described decisionloop until either the bar code symbol disappears from the scan field ortimer 64 elapses, whichever occurs first. If after timer 64 has elapsedand output O₁ has been reset, then the control program finally enters alast decision loop, to determine if first control activation signal A₁at input I₁ has gone low, indicative that an object is no longer in thescan field. If it has, then the control program returns to start, asindicated in FIG. 9B. Otherwise, until input I₁ goes low, indicatingthat an object no longer remains in the scan field, the control programwill continue to progress through this decision loop.

Notably, using the high level flow charts of FIGS. 10A and 8C, a controlprogram for the third control means 13 can be implemented in astraightforward manner for System-Control Operation No. 3, illustratedin FIGS. 10B and 10C.

Having described the detailed structure and internal functions of theautomatic bar code symbol reading system hereof, it is now proper atthis juncture to describe the operation of its control (sub)system, foreach of the three illustrated user-selectable System-Control OperationsNos. 1, 2, and 3.

Referring to Blocks A to G in FIGS. 10A and 10B, Systems-ControlOperation No. 1 is illustrated. Beginning at Block A, the bar codesymbol reading system is turned ON or powered-up, which results insystem activation means 2 being enabled (i.e., ON), while the remainderof the systems components (i.e., scanning means 3, photoreceiving means4, A/D conversion means 6, bar code symbol detection circuit 5, symboldecoding means 7, data format conversion means 8, data storage means 9and data transmission means 10), being disabled (i.e., OFF). At Block B,the control system then determines whether first control means 11detects the presence of first control activation signal (i.e., A₁ =1).If not, then the control system returns to Block A; otherwise, if so,then as illustrated at Block C, first control means 11 directly enablesscanning means 3, photoreceiving means 4 and bar code presence detectioncircuit 5.

Then at Block D, second control means 12 detects the presence of secondcontrol activation signal (i.e., A₂ =1) within first predetermined timeperiod T₁. If A₂ =1 is not present, then the control system returns toBlock A; and if so, then as indicated at Block E, second control means12 overrides first control means 11 and indirectly enables scanningmeans 3, photoreceiving means 4, A/D conversion means 6, and symboldecoding means 7.

At Block F, third control means 13 then detect the presence of thirdcontrol activation signal (i.e., A₃ =1) within second predetermined timeperiod T₂. If A₃ =1 is not present within T₂, then the control systemreturns to Block A; and if so, then as indicated at Block G, thirdcontrol means 13 overrides first and second control means 11 and 12, andindirectly enables data format conversion means 8, and data storagemeans 9 or data transmission means 10 until these functions areachieved, and therewhile disables scanning means 3, photoreceiving means4, A/D conversion means 6 and symbol decoding means 7. Thereafter, asshown in FIGS. 10A and 10B, the control system returns to Block A, whereonly system activation means 2 is enabled

Referring to Blocks A through K in FIGS. 10A and 10B, System-Control(override) Operation No. 2 is illustrated. This system-control operationoffers the advantage of being able to avoid multiple reading of bar codesymbols due to the scanning beam dwelling on a bar code symbol for anextended period of time.

Essentially, System-Control Operation No. 2 comprises but the lastreturn operation of above-described System-Control Operation No. 1 andthose additional operations represented Blocks G through K. Afterleaving Block G, third control means 13 detects the absence of firstcontrol activation signal (i.e., A₁ =0); and if absent, then the controlsystem returns to Block A. If first control activation signal A₁ is notabsent but rather present (i.e., A₁ =1), then third control means 13indirectly enables through overridden first control means 11, scanningmeans 3 and the photoreceiving means 4, and through overridden secondcontrol means 12 indirectly enables A/D conversion means 6 and bar codepresence detection circuit 5. Thereafter, at Block J, third controlmeans 13 detects the absence of second control activation signal (i.e.,A₂ =0) within predetermined time period T₃. If signal A₂ is absent, thenthe control system returns to Block A; and if signal A₂ is present(i.e., A₂ =1), then third control means 13 enters a decision loop atblock K. Here, third control means 13 in its override mode continuallydetects the absence of the first activation signal (i e. A₁ =0), atwhich time the control system returns to Block A. Referring to Blocks Athrough G and H'through J'in FIGS. 10A, 10B and 10C, System-ControlOperation No. 3 is illustrated. This system-control operation offers theadvantage of being able to simply read bar code symbols in inventoryapplications, while conserving battery power.

Essentially, System-Control Operation No. 3 comprises all but the lastreturn operation of above-described System-Control Operation No. 1 andthose additional operations represented by Blocks H' through J'. Afterleaving Block G, third control means 13 enables, through overriddenfirst control means 11, scanning means 3 in a pulsed mode of operation(by providing a pulsed enable signal E₁ ' to laser driver 37). At BlockH', third control means 13 also enables through overridden first controlmeans 11, photoreceiving means 3, and through overridden second controlmeans 12, enables bar code presence detection circuit 5, and A/Dconversion means 6.

Thereafter at Block I', third control means 13 detects the presence ofsecond control activation means (i.e., A₂ =1) within a fourthpredetermined time period T₄, determined using an internal timer similarto timer (T₃) 64 in FIG. 9A. Preferably, the time duration of T₃ isselected to be about 5-10 seconds. If signal A₂ is not present butrather absent (i.e., A₂ =0), then the control system returns to Block A.Otherwise, if signal A₂ is present, then third control means 13 enables,through overridden second control means 12, symbol decoding means 7.Thereafter, the control system returns to Block F, shown in FIG. 10A.

Having described the operation of the control subsystem of the bar codesymbol reading system of present invention, it can also be helpful tounderstand the various states that system may be in during the course ofeach particular system-control operation described above. In thisregard, reference is made to FIG. 11 which provides a state diagram forthe three system-control operations of the illustrated embodiment.

System-Control Operation No. 1 selected at option path 1, will beconsidered first. As illustrated in FIG. 11 when bar code symbol readingsystem is turned ON, only system activation means 2 is operative and allother system components are inoperative. This condition is indicated byState A, in which the device seeks to determine whether an object is inthe scan field. Upon determination of the presence of an object in thescan field, the system will undergo State Transition B, placing thesystem in State C.

In State C, the device seeks to determine within line T₁ the presence ofa bar code in scan field, while under the control of first control means11. If no bar code symbol is determined to present in the scan fieldwith time period T₁ then the system will undergo state transition D,returning the device back to initial State A (indicated as "start" inFIG. 10A). 0n the other hand, if a bar code symbol is determined to bepresent in the scan field within time period T₁, then the system willundergo State Transition E, placing the system in State F.

In State F, the system collects bar code scan data D₁ under the controlof second control means 12, converts scan data D₁ into scan data D₂ anddecode processes this scan data, scan-line by scan-line, in an attemptto decode a valid bar code symbol within time period T₂. If a bar codesymbol is not decoded within time period T₂, then the system undergoesstate transition H, returning the device to initial State A. If on theother hand a valid bar code symbol is decoded within time period T₂,symbol character data D₃ produced, and then the system undergoes StateTransition G, placing the system in "control-override" State I.

In State I, the system, while under control of the third control means,converts the data format of symbol character data D₃ into either data D₄or D₅ depending on whether the converted symbol character data is to bestored or transmitted to CMOS memory 144. Also in State I, the systemeither stores data D₅ in storage means 9, or transmits data D₅ to CMOSmemory 144 via data transmission means 10 and cable 108, shown in FIG.4. After completion of the above functions, the system undergoes StateTransition J (due to user-selection of System-Control Operation No. 1),returning the system to initial State A, completing a full path throughSystem-Control Operation No. 1.

System-Control Operation No. 2, selected at option path 2, will now beconsidered. From control override State I, the system undergoestransition K, due to user-selection of System-Control Operation No. 2,placing the system in control-override State L. In State L, the systemdetermines the presence of an object in the scan field, while under theoverride control of third control means 13. Upon determination of thepresence of an object in the scan field, the system undergoes StateTransition M, placing it into State O. On the other hand, if no objectis determined to be within the scan field, then the system returns toinitial State A.

In State O, the system seeks to determine the presence of a bar codesymbol within the scan field, while the system is under the control ofthird control means 13. If the system determines that no bar code symbolis within the scan field, then the system undergoes State Transition Q,returning the system to initial State A. If on the other hand the systemdetermines that a bar code symbol lies within the scan field, indicativeof the scanning beam dwelling on a bar code symbol for an extendedperiod of time, then the system undergoes State Transition P, placingthe system in control-override State R.

In State R, the system discontinues scanning, photoreceiving and barcode presence detection functions under the control of third controlmeans 13, and continues to sense the presence of the object in the scanfield until the object is removed therefrom. When the presence of theobject is no longer detected within the scan field, then the systemundergoes State Transition S, returning the system to initial State A.

Lastly, System-Control Operation No. 3, selected at option path 3, isnow considered. From control-override State I, the system undergoesState Transition T, due to user-selection of System-Control OperationNo. 3, placing the system in control-override State U. In State U,scanning means 3 is enabled in a pulsed-mode of operation under controlof third control 13, photoreceiving means 4 and bar code presencedetection circuit 5 are also enabled under third control means 13, andtherewhile the system seeks to detect the presence of a bar code symbolin the scan field within fourth predetermined time period T₄. If a barcode symbol is not detected within time period T₄, then the systemundergoes State Transition V and returns to initial State A underoverride control of third control means 13. If on the other hand, thepresence of a bar code symbol is detected within time period T₄, thenthe system undergoes State Transition W, placing the system incontrol-override State X.

In State X, bar code scan data is collected scan-line by scan-line, andeach scan line of data is decode processed in order to decode a validbar code symbol. If a bar code symbol is decoded within time period T₂,then symbol character data D₃ is produced and the device undergoes StateTransition Y, placing system in control-override State I under thecontrol of third control means 13. There, symbol character data D₃ isformat converted, and stored or transmitted as hereinbefore described.Thereafter, the bar code symbol reading system returns to State U undercontrol of the third control means. If, however, a bar code symbol isnot decoded within time period T₂, then the system undergoes statetransition Z, returning the system to State A while under the control ofthird control means 13.

While the system of the present invention has been provided with threeuser-selectable system-control (i.e., intelligence) operations,additional system-control operations may be provided to the controlsystem hereof, in a manner as discussed hereinabove.

Thus, in accordance with the present invention, an infrared transmitteris powered at all times while the laser scanning engine is turned off,and an infrared receiver and associated control circuitry automaticallydetect the presence of an object within the scan field of the laserscanning engine. The infrared receiver, upon detecting reflected energyfrom the object, activates control circuitry which activates the laserscanning beam, the laser scanner, the laser receiver and the signalprocessing circuitry of the laser scanning engine. The control systemcircuitry of the present invention is used to automatically control theprogrammed activation and deactivation of the processing and decodingcircuitry in remote unit. In order to operate the laser scanning engine,all the user needs to do is bring the laser scanning engine close to anobject bearing a symbol to be read, and automatically transmittedinfrared energy is reflected back from the object and detected so as toactivate the laser scanning engine and enabling the reading of thesymbol.

Advantageously, the laser scanning engine and remote unit of the presentinvention require only a very low level of power in the non-scanningstate, resulting in considerable power savings when a battery is used toprovide completely portable operations. This enhances the utility of thesystem of the present invention by eliminating requirement for anyhand-operated trigger mechanism or switch for the reading of bar codesymbols.

In FIG. 12, there is shown an alternative application the system of thepresent invention. In that application, an inventory clerk is shownusing the system for inventory control. To that end, the laser scanningengine 104 is shown mounted on a glove 136. With this arrangement, theclerk wearing the glove can scan labels affixed to bins or produces ininventory with both hands being free to handle the inventory items. Theremote unit 110 may be mounted in the same manner as that described withreference to FIG. 3.

The bar code symbol reading system of the present invention can also beused for "picking" applications, where, for example, a stock clerk isassigned to retrieve a series of items held in inventory. In suchapplications, the remote unit 110 preferably includes memory 144, asindicated in FIGS. 1 and 4, into which information identifying the itemsto be retrieved by the clerk can be entered and stored. An annunciator(not shown) is included in the remote unit 110 and coupled to itsdecoder circuitry so that when a clerk scans an item and that item isdecoded and matches the code of an item stored in memory 144, an alarmor alert signal is produced to indicate such an occurrence.

Several alternative ways of mounting the laser scanning engine 104 forhands-free operations are shown in FIGS. 13 and 14. For example, asshown in FIG. 13, laser scanning engine 104 is mounted on a hat 138 wornon the user's head in a manner similar to the mounting of a light on aminer's helmet. FIG. 14 shows laser scanning engine 104 mounted on aheadband 140 similar to the conventional headband used by a doctor tomount a light or a reflector thereon. One advantage of the mountingsystem of FIG. 14 is that when the user moves his or her head to see thesymbol to be read, the laser scanning pattern 114 is also directed tothe symbol to be read, thereby providing a somewhat automatic aimingtechnique.

Without further elaboration, the foregoing will so fully illustrate thepresent invention that others may, by applying current or futureknowledge, adapt the same for use under various conditions of service.All such adaptations and modifications of the same shall fall within thescope and spirit of the present invention defined by the appended claimsto Invention.

What is claimed is:
 1. A body-wearable laser scanning system having aprogrammed mode of automatic code symbol reading for consecutivelyreading code symbols without system reactivation, said body-wearablelaser scanning system comprising:housing support means wearable on thearm of an operator; a housing having a light transmission aperturethrough which visible light can exit and enter said housing, and beingoperably connected to said housing support means so that said lighttransmission aperture is orientable in a scanning direction; systemactivation means in said housing, for generating an activation signalfor use in activating one or more components of said body-wearablescanning system; activatable scan data producing means in said housingfor producing, when activated, scan data from an object located in atleast a portion of a scan field definable external to said housing, saidactivatable scan data producing means includinga laser beam producingmeans for producing a laser beam within said housing and projecting saidlaser beam through said light transmission aperture, and scanning saidlaser beam across said scan field and a code symbol on said object, andlaser light detecting means for detecting the intensity of laser lightreflected off said code symbol and passing through said lighttransmission aperture, and automatically producing scan data indicativeof said detected light intensity; activatable scan data processing meansfor processing, when activated, produced scan data so as to detect anddecode said scanned code symbol and automatically produce symbolcharacter data representative of said decoded code symbol; systemcontrol means for automatically activating said activatable scan dataproducing means and said activatable scan data processing means inresponse to the generation of said activation signal, and controllingthe operation thereof during said programmed mode of automatic codesymbol reading such that two or more code symbols on one or more objectsin said scan field can be consecutively detected and decoded withoutreactivation of said activatable scan data processing means or saidactivatable scan data processing means; and battery power supply means,supportable on the body of said operator, for supplying electrical powerto said system activation means, said activatable scan data producingmeans, said activatable scan data processing means, and said systemcontrol means.
 2. The body-wearable laser scanning system of claim1,wherein said code symbol is a bar code symbol, and wherein said barcode symbol has first and second envelope borders, and said activatablescan data processing means detects said bar code symbol by detectingsaid first and second envelope borders.
 3. The body-wearable laserscanning system of claim 1, wherein said system activation meanscomprisessignal transmitting means for transmitting a signal into saidscan field, and signal receiving means for receiving said transmittedsignal reflected off said object in at least a portion of said scanfield, and automatically generating said activation signal in responseto receiving said transmitted signal.
 4. The body-wearable laserscanning system of claim 3, wherein said signal transmitting meanscomprises an infra-red light source for transmitting a pulsed infra-redlight signal, and wherein said signal receiving means comprises aninfra-red light detector and an optical element for focusing reflectedinfra-red light pulses onto said infra-red light detector.
 5. Thebody-wearable laser scanning system of claim 1, wherein said housingsupport means comprises a glove wearable about the hand of saidoperator.
 6. The body-wearable laser scanning system of claim 5, whereinsaid glove allows the finger of said operator to be exposed when wornabout the hand thereof.
 7. The body-wearable laser scanning system ofclaim 1, wherein said laser beam producing means comprises a laser diodefor producing a visible laser beam.
 8. The body-wearable laser scanningsystem of claim 1, wherein said scanning direction is oriented along thepointing direction of the fingers of said operator.
 9. The body-wearablelaser scanning system of claim 1, which further comprises a remote unitcontaining said activatable scan data processing means, said systemcontrol means and said battery power supply means.
 10. The body-wearablelaser scanning system of claim 1, which further comprises a radiofrequency signal transmission means in said remote housing, fortransmitting symbol character data to a peripheral device by way ofradio frequency signal transmission.
 11. The body-wearable laserscanning system of claim 1, wherein said housing support means iswearable on the back of the hand of the operator.